The invention relates to a method of setting flat elements in relation to a reference device, in particular stamping dies or the like, and for aligning embossing printing blocks relative to an embossing original outside a stamping machine, by means of a camera and picture screen associated therewith. In addition the invention concerns a corresponding apparatus which can also be used for carrying out the method.
German laid-open application (DE-OS) No 39 17 919 discloses a table for positioning elements on a carrier in accordance with reference documents, comprising a plate on which the reference document lies and over which a first video camera carried by a carriage is displaceable in a parallel plane. The carriage is movable along a traverse member which in turn is movable laterally along the plate with the carriage. A second camera which is carried by an arm which is movable along a bridge can be displaced over a working plane in a parallel plane, wherein the arm and the bridge can each be moved by a respective electromechanical drive device. Control of the electromechanical drive devices for moving the bridge and the arm of the second camera is effected so that the latter is displaced relative to the movements of the first camera, which movements are controlled by a manipulator and are detected by first position detectors mounted on the carriage, the traverse member and the plate, the electronic control device monitoring the degree of accuracy of the movements of the second camera in order to permit same to perform complementary movements.
The previously known apparatus is technically complex as two separate systems are required and in addition it involves considerable costs.
The embossing original required is heated and distorts, which results in inaccuracies. Added to that are deviations as between the two systems due to inevitable geometry flaws in the two guide systems.
Cardboard or pasteboard boxes are stamped out with so-called steel strip cutting tools. Steel strip cutting tools are stamping or punching dies in which strip-shaped blades and fold lines, following the contours of the cardboard or pasteboard boxes, are arranged in slits in a plate (preferably a multi-layer plywood plate). For use in automatic stamping or punching machines, the steel strip cutting tools are clamped in holding frame structures.
Many higher-grade cardboard or pasteboard boxes are provided with embossings, on account of the pleasant appearance. Embossings may be on the one hand hot foil embossings in which colored, shiny and/or metallized foils are embossed on to the blanks under the effect of heat, while on the other hand it is also possible to refer to embossing when the material is deformed in a relief pattern by embossing blocks. Relief embossing can also be effected by using hot foils or on the sheet with or without printing thereon.
Whichever method is employed, because of the high requirement in terms of quality concerning positional accuracy of the embossing blocks relative to the sheet of material, it is necessary to reckon on extremely long setting times at the stamping machines.